The long-range goal of this study is to elucidate the chemical nature and relevant biological role of Cystic Fibrosis cilioinhibitory factors. Within this context we specifically aim: to develop methods that allow chemical differentiation and isolation of those cilioinhibitory serum factors that are specifically associated with the Cystic Fibrosis trait; to purify those factors and determine their chemical struture; and to delineate a spectrum of their biological activities that may furnish insight into their role in the pathogenesis of Cystic Fibrosis. We propose to develop methods for stabilizing the original in vivo activity of source materials during collection, storage and processing; to isolate and analyze putative small peptides of interest from Cystic Fibrosis homozygote and heterozygote serum, parotid and submaxillary saliva, and to screen these purified peptides for potential effects on membrane permeability, membrane transport, smooth muscle contractility, and arterial blood pressure in a number of isolated model systems.